Post on 11-May-2020
WALNUT NUTRITION
How to Develop a Balanced
Program
Bob Beede, UC Farm Advisor
Kings County
http://cekings.ucdavis.edu/
Nutrition Management Involves
Knowledge of:
• Site/Soil characteristics and chemistry
• Plant requirements
• Cropping history
• Fertilizer inputs
• Cultural practices (Irrigation, vegetation management, pruning)
• Tissue analysis
• Observation and judgement
MOST PLANTS REQUIRE 14 ESSENTIAL
ELEMENTS FOR NORMAL GROWTH AND
REPRODUCTION
THESE ELEMENTS ARE GROUP INTO TWO
CATEGORIES, BASED ON THE QUANTITY
REQUIRED (MACRO=LARGE, MICRO=SMALL)
MACRONUTRIENTS:
NITROGEN (N)
PHOSPHORUS (P)
POTASSIUM (K)
CALCIUM (Ca)
MAGNESIUM (Mg)
SULFUR (S)
MICRONUTRIENTS:
IRON (Fe)
MANGANESE (Mg)
BORON (B)
COPPER (Cu)
ZINC (Zn) MOLYBDENUM (Mo)
CHLORINE (Cl) NICKEL (Ni)
How are nutrients obtained?
Soil Science and Plant Nutrient Uptake
Nutrients are taken up in water only by active roots.
– Active root growth is required.
– Water, oxygen, suitable temperatures are required for uptake
– Leaves are required for nutrient uptake by roots
N, S, Mg, Ca, B are mobile in most soils
– Water movement delivers these nutrients to roots
Mn, Zn, Cu, Ni, Fe have restricted solubility and movement in soils, hence:
– Active root growth and soil exploration are critical
– Nutrients and roots must be in the same place
– Soils that limit root growth can cause Zn, Fe, Cu deficiencies
K is mobile in some soils but not others
– Soil tests to determine K-fixation are essential to K management.
Annual Leaf Tissue Sampling:
• A plant-based measurement which
integrates all the factors associated with
nutrient extraction from the soil that it
inhabits.
• Provides cause for further evaluation of soil
and water quality, and fertilization practices.
•Best performed in July. Sample good and
bad trees separately. Sample trees suspected
of deficiency any time. Compare to good
trees.
What approaches do we have to manage and optimize nutrition?
Leaf Samples and Critical Values for Walnut
Concerns:
• Validated for mid-summer samples only.
• Limited guidance provided on how to sample effectively or respond
appropriately.
Nitrogen <2.1 2.2 - 3.2
Potassium 0.9 >1.2
Zinc 18
Boron 20 36-300 >300
Deficient Adequate Toxic
Soil type and texture, pH and irrigation water
all affect nutrient availability
Effect of Soil pH:
pH >7.5 < Zn, Cu, Mn, Fe
pH < 6.0 < P, Ca, B
• Old river beds, sandy soils, cuts or fills, old corrals,
alkali patches, etc.)
• Soil series: Mg, K availability (dolomite, gypsum,
lime)
• Irrigation waters differ in nutrient content
Value of Soil Testing (How and Why)
How:
• Collect soil samples that reflect where roots will be growing
• Collect samples from all parts of the orchard and build a ‘map’ of the whole property. Do it and do it right, most soil characteristics don’t change with time.
What:
• Soil tests that provide background information on general soil physical and chemical characteristics are essential for all orchards.
• pH, Lime/Bicarbonate - as an index of potential solubility of natural and applied nutrients
• CEC, OM as a measure of buffering capacity
• Salinity, Toxic Elements, nutrient imbalances.
• Determine K fixation characteristics.
• For most nutrients (with the exception of K, B), soil analyses of nutrient availability are of limited value.
Central Valley Coalitions Sacramento Valley Water Quality Coalition
• Bruce Houdesheldt
California Rice Commission
• Tim Johnson
Goose Lake Water Quality Coalition
San Joaquin County & Delta Water Quality Coalition
• Michael Wackman
Westside San Joaquin River Watershed Coalition
• Joseph C. McGahan
• David Cory
East San Joaquin Water Quality Coalition
• Parry Klassen
• Wayne Zipser
Southern San Joaquin Valley Water Quality Coalition
• David Orth
Westlands Coalition
• Sue Ramos
13
Grower Responsibilities
Complete Farm Evaluation (everyone)
Complete Nitrogen Management Plan (In high vulnerability groundwater area)
• Certified by 3rd party or grower trained
• Low vulnerability keep on site; no certification required
Sediment and Erosion Control Plan (In areas identified as high vulnerability for erosion and sediment discharge)
More time provided for farming operations < 60 acres total
What Will Be Required
Farm Management Plans
Template to be developed by coalitions, reviewed by Water Board
Report practices “protective of surface and groundwater quality”
Periodic Updates
More frequently in high vulnerability areas
Deadline for reports • High vulnerability: 2014
• Low Vulnerability: 2017 (keep on farm)
15
Nitrogen Management Plans
Key mechanism to minimize nitrogen discharge
to surface and groundwater
High Vulnerability Areas
• CCA certifies nitrogen budgets for members • CDFA certification program in development
• Member self-certification with training
• Plans kept on site, summary info reported to
Coalition
Low Vulnerability Areas
• Required but keep on farm
Nitrogen Management Plan
Components
Apply N at crop removal rates • Dairies regulated to 140% of crop use (N applications)
Test well water for nitrogen levels (then adjust N applications accordingly)
Leaf / tissue testing
Soil testing
Deadline for reports • High vulnerability: 2015 for crop year 2014
• Low Vulnerability: 2017 (keep on farm)
Annual Nitrogen Budget CROP NITROGEN DEMAND Crop Nitrogen Needs/Uptake NITROGEN SUPPLY Credits and Applications
Crop
WALNUT
Expected yield (Lbs of Production/acre)
6000
Nitrogen Crop Needs to meet Excepted yield (lbs of Nitrogen per acre)
200
Nutrients: Total N applied to field Nitrogen fertilizers (conventional and organic)
Spring Summer Fall Folair fertilizers Other fertilizers
Manure Compost Bacterial extracts/Compost teas Other nutritional product
TOTAL N Applied Soil Nitrogen Credits Soil N ppm³ Lbs N/acre
Nitrogen from previous legume crop Residual from long-term manure applications Soil organic matter mineralization Current soil test levels⁴ Irrigation water nitrogen credits (annualized) (10PPM NITRATE N= 27 LBS N PER ACRE FOOT)
75
125
0
0
0
0
0
0
200
0
10
5
10
55
TOTAL N CREDITS 80
Totals N Credit and Applications:
Crop N needs:
Balance:
Ratio:
280
200
90
1.40
Nutrient Fluxes (N, K, S, P) in Walnut
Stored Nutrients Current Year Uptake
0
50
100
150 Excess Demand
Environmental Constraints
Cold Spring or Drought
N F
lux
(mg N
/da
y/tre
e)
The scale of nutrient
demand is determined
largely
by Yield
Spring Growth
Flowering
Leaf Expansion Nut
Development Nut maturity
Bud development Nutrient Storage, leaf senescence
Composition of walnut
Weinbaum N Experiment
1984-1990
Studied N utilization, efficiency of N recovery
using isotopic labeled NH SO 4 4
Yield reduction in Serr and Hartley
corresponded to midsummer leaf N
concentrations below 2.3% dry weight.
Yield recovery requires a minimum of 2 years
after N re-application, even though tissue N
levels recover in one year.
Weinbaum N Experiment
1984-1990
Approximately 110 lbs/ac of N was removed annually
from the orchard in the form of fruit, prunings, and
leaves. 80% of the consumed N was in the fruit.
65% of leaf N was transported back into the
fruitwood before leaf fall!
Depending upon fertilizer application method, time
of application, and irrigation uniformity, about 150-
200 lbs actual N should be applied annually as a
maintenance program.
Weinbaum N Experiment
1984-1990
The rate of uptake is function of demand and availability.
Approximately 50% of the N within the walnut tree is replaced
annually by soil N.
PHOSPHOROUS DEFICIENCY: VOLCANIC PARENT
MATERIAL, MT. KONOCTI, LAKE COUNTY
PHOSPHORUS DEFICIENCY: LEAF BROWNING AND DROP,
BEGINNING AT THE BASE OF THE SHOOT
POTASSIUM DEFICIENCY IN WALNUT
Role of Potassium
1. Taken up in ionic form (K )
2. Unlike nitrogen, K is not synthesized into compounds,
but remains largely in ionic from within cells and tissues
3. K essential for transport of sugars and formation of
starch (complex sugar)
4. Regulates stomata through the guard cells
5. Promotes root growth
6. Reduces potential for disease infection
7. Increases fruit size and quality
8. Increases winter hardiness
+
+
+
Potassium Potassium Potassium Potassium
Chloride Sulfate Nitrate Thiosulfate
KCL K₂SO₄ KNO₃ K₂S₂O₃
% K₂O 62 50 46 25
Solubility 34gr/100 11gr/100 31.6gr/100 155gr/100
20⁰C H₂O
Cost per
Ton $695.00 $770.00 $0.85/lb $700.00
Cost per
Ton K₂O $1,121.00 $1,540.00 $2,353.00 $2,800.00
250 lb of
K₂0 $140.00 $192.50 $294.00 $350.00
Note: K₂O X .83 = K
Annual walnut K requirement estimated at
61 lbs K₂O per year for 2 ton crop
Properties of Potassium (K ) Salts
Bill Olson K Experiment
(UC Farm Advisor, Emeritus, Butte County)
1984-1990
A. Two trials in K deficient walnut orchards
1. Orchard 1 (1984): Clay loam
B. Treatments (all KCL):
1. 1000 lbs/ac drilled one time
2. 400 lbs/ac banded both sides 6ft from
trunk annually in Nov.
3. 400 lbs/ac fertigated in sprinklers 4X annually
(100 lbs each)
4. 1500 lbs/ac banded in 1986
5. 1500 lbs/ac banded in 1986-88, and 400 lbs
banded in 1989
6. Untreated check
Olson K Experiment
1984-1990
Orchard 1 results (clay loam)
1. Five years required before annual 400lbs.
KCL treatment corrected deficiency
2. Banded applications better than sprinkler
3. Single 1000 lbs. treatment only slightly effective
4. Single and multiple 1500 lbs. treatments both showed
Immediate and continued tissue K improvement
Bill Olson K Experiment
1984-1990
Orchard 2 (1987): Sandy loam
Treatments (all KCL applied with Ranchero spreader):
1. 400 lbs/ac banded annually in Nov.
on both sides 6 ft from trunk
2. 400 lbs/ac banded annually in Nov.
in center of row
3. 1600 lbs/ac banded once in 1987
4. Untreated Check
Bill Olson K Experiment
1984-1990
Results
Orchard 2 (Sandy loam):
All Treatments provided correction
MICRONUTRIENT DEFICIENCIES IN NUT CROPS:
HOW COMMON ARE THEY?
ALMONDS 3 2 2 0 2 0
WALNUTS 3 1 0 0 2 0
PISTACHIOS 3 3 0 3 2 0
PECANS 3 0 0 0 2 0
Zn B Fe Cu Mn Ni
VISUAL SCALE: 0= never seen, 1= rarely, 2= occasional, 3= often
The Role of Zinc in Plants
1. Required for Auxin (NAA) formulation
2. Auxin involved in cell elongation
3. Associated with chloroplast formulation
4. Essential for pollen development, flower
bud differentiation and fruit set
Diagnosing Zinc Deficiency
1. Visual symptoms
2. Consider soil chemistry
3. Rootstock: Nemaguard > Lovell >
Marianna
4. Variety: Plum > Peach, Nectarine
– Friar, Blackamber
Diagnosing Zinc Defieiency (continued)
5. Tree vigor
6. Nitrogen source:
– High Phosphorous (manure) ties up Zinc
7. Weather/Spring irrigation source
8. Tissue analysis
Factors Affecting Soil-
Zinc Availability
1. pH
– Solubility decreases 100 fold for each unit
increase in pH
• pH 5 = 10-4 M (6.5 ppm)
• pH 8 10-6 M (0.007 ppm)
2. Cut areas likely to be more deficient
Factors Affecting Soil-
Zinc Availability
3. High Magnesium or Phosphorous reduces
Zinc availability
4. Methyl Bromide fumigation causes
temporary loss of mycorrhizal fungi
5. Calcareous materials (lime) reduce Zinc
availability
Tissue Sampling for
Zinc Deficiency
1. Compare leaves of similar age from trees
with and without symptoms
2. Sample leaves with symptoms
3. Do not sample leaves sprayed with zinc
Correcting Zinc Defieiency
Soil:
1. Expensive
2. Less effective due to fixation
Root
M++
Root
Hair
Mobilization of soil metal ions by chelates (after Lindsay [1974])
Chelate
Soil Particles
M-
Chelate
M++ M+++
Correcting Zinc Defieiency
Foliar
1. Effective
2. Safe with correct material for desired time
3. Concentrate (100 GPA) safer than dilute
(300-400 GPA)
SPRING FOLIAR TREATMENT RECOMMENDATIONS FOR NUT CROPS:
ALMONDS:
A. CHLEATED ZINCS OR ZIRAM AT PETAL FALL WHEN ADEQUATE
FOLIAGE EXISTS
B. WHEN RAIN UNLIKELY, 10 LBS/AC BASIC ZINC SULFATE IN
100 GALS. APPLIED ONCE OR TWICE, 3 WEEKS APART.
C. ADD ZN COMPATIBLE WITH COVER SPRAYS DURING SEASON
WALNUTS:
A. 3-4 LBS/AC 36% ZN IN 100GPA APPLIED POST-BLOOM AT 6-
10” OF SHOOT GROWTH. REPEAT IF ZINC SYMPTOMS SEEN
B. FOR SEVERE DEFICIENCY, APPLY ONE LB. ZN EDTA 14%
PER TREE, 4-5’ FROM TRUNK, IN A SMALL TRENCH. COVER.
C. SURVEY TREES> 40’ FOR ZINC IN UPPER CANOPY. TREAT
BY AIR WITH 36% OR CHELATE
Shoot Zn
Distribution
Through
A
Dormant
Peach
Tree
(ppm)
47.9 - shaded
39.7 - sun exposed
16.3
32.6
water sprout
19.1 - sun exposed
28.5 - sun exposed
70.3 - shaded
Boron Boron is a Building Block for the cell wall and
hence all Growth, especially flowers and fruits.
• Nutrient Uptake and Assimilation
– Uncharged element, not fixed in CA Walnut soils. Deficiency can occur in all soils supplied with low B irrigation water.
– Stored in organic residue.
• Function
– Cell Wall Construction
– Pollen formation and fertilization
• Mobility
– Highly immobile in Walnut
– Lack of mobility and high demand for reproduction can result in critical short term deficiencies that are hard to detect or predict but are potentially very important.
The occurrence of B deficiency and the
response to B sprays has been
inconsistent but occasionally very
significant.
Boron demand and B response is hard
to predict .
Methyl Bromide Alternatives Trial-Kings County
Bob Beede, UC Kings Co. Farm Advisor
Mike McKenry, Extension Specialist Riverside
Dan Kluepfel, USDA-ARS Davis
Tony Garcia, Kings Co. Ag. Assist.
USDA-ARS and UC GIVE GREAT THANKS
To Tri-Cal, Inc. for their superior support!
Local Reps:
Bob Montgomery
Ramon Sanchez
Treatments
1 - White: Untreated Control 2 - Pink: Methyl Bromide broadcast at 400 lb/ac. 3 - Yellow: Telone II at 33.7 g/ac strip-treated (10’
swath) and shanked at 20”. 4 - Blue: Telone II at 33.7 g/ac broadcast and
shanked at 20”. 5 - Orange: Telone II at 33.7 g/ac broadcast and
shanked at 20” plus Chloropicrin at 175 lb/ac shanked at 28”.
6 - Green: Telone II at 33.7 g/ac broadcast and shanked at 20” plus Methyl Bromide at 125 lb/ac shanked at 28”
Kings County Fumigation Trial
Cooperator : Doug Verboon
Spacing: 25' Between Rows: 40' between Trees
Plots: 12 trees (6 Paradox Seedlings, 6 VX211) Tulare Cultivar
TOTAL ACREAGE: 13.14
450'
Buffer Buffer Buffer Buffer Buffer Buffer
Paradox Paradox Paradox Paradox Paradox Paradox
BLK 1 T-5 T-2 T-3 T-6 T-4 T-1 200'
VX211 VX211 VX211 VX211 VX211 VX211
Buffer Buffer Buffer Buffer Buffer Buffer
BLK 2 T-2 T-5 T-4 T-1 T-3 T-6
1300' Buffer Buffer Buffer Buffer Buffer Buffer
BLK 3 T-3 T-6 T-1 T-2 T-5 T-4
Buffer Buffer Buffer Buffer Buffer Buffer
BLK 4 T-4 T-1 T-6 T-5 T-2 T-3
Buffer Buffer Buffer Buffer Buffer Buffer
BLK 5 T-1 T-3 T-2 T-4 T-6 T-5
Buffer Buffer Buffer Buffer Buffer Buffer
BLK 6 T-6 T-4 T-5 T-3 T-1 T-2
Buffer Buffer Buffer Buffer Buffer Buffer
12 Avenue
Dirt Road Between Young Walnuts and New Planting Site
FUMIGATED Two-year-old Tulare Scion
OCTOBER 27, 2010
NO FUMIGATION CONTROL
SAME TREE AGE
OCTOBER 27, 2010
Walnut Replant Trial
Effect of pre-plant fumigation on first –year production of “Tulare” walnuts in a
replant situation. Averages based on six .35 acre plots in a Latin Square Design.
October 10, 2012
Ave
rage
In-S
hell
(lbs.
)
Efird Farms, 2012
EFFECT OF RETAIN TIMING AND
CONCENTRATION ON REDUCING SERR
WALNUT PISTILLATE FLOWER
ABORTION
104
115
124 127 130
135
164
0
20
40
60
80
100
120
140
160
180
Untreated 15-20% Bloom
30-40% Bloom
50-60% Bloom
15-20% 30-40%
30-40% 50-60%
4 sprays (15 - 85% Bloom)
AV
E.
DR
Y IN
SH
EL
L W
T.
(lb
/tre
e)
TREATMENT
b b
ab ab ab
ab
2011 ReTain Timing Trial: Efird Farms Data represents average dry wt yield of seven single trees
Rate per application: 1 bag/ac, 200 gpa (50 tree/ac)
a
2012 Retain Trial Effird Farms Yield Data A
vera
ge D
ry I
n S
hell W
eig
ht
Treatment
THANK YOU!
HAPPY FARMING!
THANKS TO ALL OUR
SPONSORS!
Zinc
• Nutrient Uptake and Assimilation – Walnut (and Pecan) are very sensitive to low Zn.
– Zn2+ is a charged ion easily immobilized ‘fixed’ in the soil
– Deficient in alkaline (pH>7), bi-carbonate rich soils (co-precipitation of
Fe-Oxides), leached acid soils and organic rich soils.
– Soil fertilizers must overcome this fixation (Chelates, high local
concentrations and bands) or foliars.
• Function – Key roles in gene regulation and protein synthesis (bud break and shoot
extension)
– Alters stress tolerance (high light, drought, disease?)
• Mobility – Phloem immobile or slightly mobile in walnut in the fall and spring.
– Limited foliar uptake into mature leaves.
Nitrogen, Potassium, Sulfur, Phosphorus,
Magnesium, Calcium
Essential for all stages of plant growth.
• N, K and P exported in the crop should be replaced to avoid soil depletion (yield drives fertilization)
• K, S, P, Mg are mobile in plants and can be effectively stored for later use (1 fertilization - prolonged effect)
• K response is highly soil specific
– Conduct soil tests and follow soils consultant advice
• N is mobile in plant and soil and can be lost to the environment
– apply only when the tree is growing actively.
• S, Mg, Ca and P are rarely deficient in CA soils
– S is supplied in K, Ca and Mg sulfate fertilizers, if none of these are used S monitoring is recommended.
• Ca is important for growth and is immobile,
– some responses to in-season foliar Ca at flowering have been reported.
When are nutrients required?
Nutrient Demand Is Not Uniform Through the Year.
Uptake only occurs in actively growing plants
– No uptake in fall, winter or before leaf out.
For N and K yield determines demand
– The size of the crop determines the demand for N and K
Short Term Nutrient Deficiencies can be important (transient)
– During times of High Nutrient Demand
• Heavy crop, marginal supply.
– When Environmental Conditions prevent uptake
• Cold weather at flowering
• Drought
– For immobile elements with critical short term demand
• Zinc during spring growth
• Boron during flowering
1984-2004
2005-2010
68
Grower Responsibilities
Farm Management Practices performance standards (everyone)
• Minimize waste discharge offsite in surface water,
• Minimize percolation of waste to groundwater,
• Minimize excess nutrient application relative to crop need,
• Implement effective sediment discharge and erosion prevention
practices to minimize or eliminate the discharge of sediment
above natural background levels
• Prevent pollution and nuisance,
• Achieve and maintain water quality objectives and beneficial uses
• Protect wellheads from surface water intrusion.
New Program Requirements
Waste Discharge Requirements Irrigated Lands Regulatory Program
Groundwater Assessment Report
• Rank land vulnerability based on Assessment Report
• High Vulnerability
Areas ID’d using DPR pesticide groundwater protection areas, State
Water Board vulnerable areas
• Low Vulnerability
• Keep farm assessment / nitrogen budgets on farm
Agenda Item 13 70
Central Valley Water
Board Meeting June
2012